Inter-Tool Communication Flow Control in Toolbus System of Cable Telemetry

ABSTRACT

Systems and methods for inter-tool communication in toolbus systems in cable telemetry. The systems can include downhole equipment deployable into a wellbore via a cable, The downhole equipment can include a toolbus, a toolbus master node including a buffer, and nodes operatively coupled to the toolbus master node via the toolbus. Each of the nodes includes a buffer. Of the one or more nodes, a sending node sends a message, and a receiving node receives the message via the toolbus master node and sends a buffer full message to the toolbus master node when the buffer of the receiving node is full. The toolbus master node sends a buffer full message to the sending node and the receiving node when the buffer of the receiving node is full, and buffers the message at the toolbus master node until the receiving buffer is not full.

BACKGROUND

The following descriptions and examples are not admitted to be prior artby virtue of their inclusion in this section.

Hydrocarbon fluids, such as oil and natural gas, may be obtained from asubterranean geologic formation, referred to as a reservoir, by drillinga well that penetrates a hydrocarbon-bearing formation. A variety ofdownhole tools may be used in all areas of oil and natural gas services.In some cases, downhole tools may be used in a well for surveying,drilling, and production of hydrocarbons, The downhole tools maycommunicate with the surface via various telemetry systems. In somecases, the downhole tools may include one or more individual modules inoperative communication with one another, such as a master module andmultiple slave modules,

With the increased precision of downhole tools and sensors, a relativelyshorter time may be available to send increasingly larger amounts ofdata. In addition to new modules and assemblies being developed fordownhole use on a continuing basis, toolbus systems may facilitatecommunication between older and newer generation modules in order toobtain the maximum service life from existing modules,

Applications of disclosed embodiments of the present disclosure are notlimited to these illustrated examples, and different industrialapplications may benefit from implementations of the followingdisclosure.

SUMMARY

In at least one aspect, the disclosure relates to a method forinter-tool communication in a toolbus system in cable telemetry. Themethod can include positioning downhole equipment into a wellbore via acable. The downhole equipment includes a toolbus master node including abuffer of the toolbus master node and one or more nodes operativelycoupled to the toolbus master node via a toolbus. Each of the one ormore nodes includes a buffer. The method can include sending a datamessage to a receiving node of the one or more nodes from a sending nodeof the one or more nodes via the toolbus master node, sending a bufferfull message from the receiving node to the toolbus master node when thebuffer for the receiving node is full, forwarding the buffer fullmessage from the toolbus master node to the sending node and thereceiving node, buffering the data message at the buffer of the toolbusmaster node when the buffer for the receiving node is full, and sendingthe data message to the receiving node when the buffer of the receivingnode is not full.

In at least one aspect, the disclosure relates to a system forinter-tool communication in a downhole toolbus in cable telemetry. Thesystem can include downhole equipment deployable into a wellbore via acable. The downhole equipment can include a toolbus, a toolbus masternode including a buffer, and one or more nodes operatively coupled tothe toolbus master node via the toolbus. Each of the one or more nodesincludes a buffer. Of the one or more nodes, a sending node sends amessage, and a receiving node (operatively coupled to the sending nodevia the toolbus) receives the message via the toolbus master node andsends a buffer full message to the toolbus master node when the bufferof the receiving node is full. The toolbus master node sends a bufferfull message to the sending node and the receiving node when the bufferof the receiving node is full, and buffers the message at the buffer ofthe toolbus master node until the buffer of the receiving node is notfull.

In at least one aspect, the disclosure relates to a method forbi-directional communication in a cable telemetry system, The method caninclude providing a cable telemetry system including a cable operativelycoupling between a surface modem and a downhole modem. The downholemodem can be operatively coupled to a downhole toolstring of downholetools. The method can include configuring one of a tool command and atool measurement into a configured transmission for communication viathe cable telemetry system, buffering the configured transmission at thesurface modem, transmitting the configured transmission via the cable,buffering the configured transmission at the downhole modem, and routingthe configured transmission to one tool of the downhole tools.

This summary is provided to introduce a selection of concepts that arefurther described below in the detailed description. This summary is notintended to identify key or essential features of the claimed subjectmatter, nor is it intended to be used as an aid in limiting the scope ofthe claimed subject matter,

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of systems, apparatuses, and methods for inter-toolcommunication flow control in toolbus systems of cable telemetry aredescribed with reference to the following figures. Like numbers are usedthroughout the figures to reference like features and components.

FIG. 1 is a schematic representation of a well site with a boreholetraversing subsurface formations.

FIG. 2 illustrates schematically an example cable telemetry systemincluding a toolbus system for monitoring subterranean formations inaccordance with an embodiment of the present disclosure.

FIG. 3 illustrates a timing schematic for inter-tool communication dataflow control in accordance with an embodiment of the present disclosure.

FIG. 4 is a flow chart for a method for inter-tool communication dataflow control in a cable telemetry system in accordance with anembodiment of the present disclosure.

FIG. 5 is a schematic diagram depicting a flow control system inaccordance with an embodiment of the present disclosure.

DETAILED DESCRIPTION

In the following description, numerous details are set forth to providean understanding of the present disclosure. However, it will beunderstood by those skilled in the art that the present disclosure maybe practiced without these details and that numerous variations ormodifications from the described embodiments are possible.

The disclosure relates to data flow control in inter-tool communicationbetween downhole tools. This may be performed without the necessity ofrouting the communication through a surface module. Inter-toolcommunication data flow control may include sending an uplink commandmessage for a receiving downhole node from a sending downhole node to amaster downhole node and sending a command buffer full message from thereceiving downhole node to the master downhole node when a receivingnode command buffer is full. The master downhole node sends a downlinkcommand buffer full message to the sending and receiving downhole nodes,buffers the uplink command message, and sends the uplink command messageto the receiving downhole node when the receiving node command buffer isnot full. Additional information may be found in the related U.S.Provisional Application No. 61/581079, filed on Dec. 29, 2011 andentitled “A METHOD AND SYSTEM FOR INTER-TOOL COMMUNICATION FLOW CONTROLIN A TELEMETRY SYSTEM,” the entire contents of which are herebyincorporated by reference herein in their entirety.

Referring to FIG. 1, an example embodiment wireline logging operation isillustrated with respect to the wellsite system 100 employed in awellbore 102 traversing a subsurface formation 104. A downhole telemetrycartridge 110 is connected to a toolstring 116. In a well-loggingoperation, a plurality of tools may be connected in the toolstring 116.The tools of the toolstring 116 communicate with the downhole telemetrycartridge 110 via a bi-directional electrical interface. The tools ofthe toolstring 116 may be connected to the telemetry cartridge 110 overa common data bus. Alternatively, each tool of the toolstring 116 may beindividually, directly connected to the telemetry cartridge 110. In oneembodiment, the telemetry cartridge 110 may be a separate unit, which ismechanically and electrically connected to the tools in the toolstring116. In an alternative embodiment, the telemetry cartridge may beintegrated into the housing of one of the well-logging tools oftoolstring 116.

The telemetry cartridge 110 is operatively coupled to a wireline cable114. The tools of the toolstring 116, including the telemetry cartridge110, may be lowered into the wellbore 102 on the wireline cable 114.

A surface data acquisition computer 118 is located at the surface end ofthe wireline cable 114. The surface data acquisition computer 118includes or couples to an uphole telemetry unit 112. The dataacquisition computer 118 may provide control of the components in thetoolstring 116 and process and store the data acquired downhole. Theacquisition computer 118 may communicate with the uphole telemetry unit112 via a bi-directional electrical interface.

The uphole telemetry unit 112 may modulate downlink commands from theacquisition computer 118 for transmission down the cable 114 to thetoolstring 116 and demodulate uplink data from the toolstring 116 forprocessing and storage by the surface data acquisition computer 118.

The downhole telemetry cartridge 110 contains circuitry to modulateuplink data from the tools of the toolstring 116 for transmission up thewireline cable 114 to the surface data acquisition computer 118 anddemodulate downlink commands from the surface data acquisition computer118 for the tools of the toolstring 116.

A more detailed schematic view of one example cable telemetry system 200is shown in FIG. 2. The cable telemetry system 200 shown includes asurface acquisition module/surface modem (DTM) 220 having a telemetryinterface module (TIM) 222, which can be located at the surface as aportion of, or operatively coupled to, the surface data acquisitionfront end 119 (a component of surface data acquisition computer 118 ofFIG. 1), coupled to the wireline cable 114, a downhole modem (DTC) 226(as a portion of the downhole telemetry cartridge 110 at the head of atoolstring 116 of FIG. 1) which includes a number of downhole tools,230, 230′, 230″, 230″, etc., each containing a respective interfacepackage (or EIP), 232, 232′, 232″, 232′″, etc., through which they arein communication with the DTC 226 via a toolbus 228. The interfacepackages may be, for example, EIP 2.0—Enhanced Interface Package 2.0commercially available from SCHLUMBERGER TECHNOLOGY CORPORATION (see:www.slb.com). The surface acquisition front-end unit 119 may alsoinclude various additional components, such as power module 221, depthand tension module 223, flow controller software module (FEPC) 224, etc.

The cable telemetry system 200 may handle data flows in oppositedirections, i.e., from the tools, etc., via the respective interfacepackage 232, 232′, etc. and the toolbus 228, to the DTC 226 and then tothe DTM 220 over the cable 114 (“uplink”), and the reverse directionfrom the DTM 220 to the DTC 226 and tools 230, 230′, etc., over the samepath (“downlink”). The cable telemetry system 200 provides acommunication path from the tools, 230, 230′, etc., to the DTM 220 ofthe data acquisition computer 118 so that data acquired by the tools,230, 230′, etc., can be processed and analyzed at the surface, as wellas communication between tools 230, 230′, etc. Each individual tool(230, 230′, etc.) may include a node command buffer (not shown) at theinterface package (232, 232′, etc.), as well as a logic controller ofits own (not shown),

The downhole telemetry cartridge 226 can include a downhole master nodecontroller 227 that may examine packets sent by each respective tool230, 230′, etc. The master node controller 227 may be, for example, anEIP 2.0 Master—Enhanced Fast Tool Bus 2.0 Master commercially availablefrom SCHLUMBERGER TECHNOLOGY CORPORATION (see: www.slb.com). Datacommunicated in either direction may be copied and buffered at themaster node controller 227, and sent to the recipient.

A surface computer 234 can store and execute a surface data dispatchermodule 236 (which may be, in an embodiment, a software data routingmodule, such as SCHLUMBERGER™'s Maxwell Framework). The surface computer234 can also store and execute a plurality of surface tool-specificapplications 238, 238′, 238″, 238″′, etc. that analyze and use dataobtained, respectively, by tools 230, 230′, etc.

In a cable telemetry system of a given configuration, each tool (230,230′, etc.) would send data (acquired and/or timing, for example) to thedownhole telemetry cartridge 226 through the toolbus 228, via theinterface package 232, 232′, etc. from tool node controller 233, 233′,etc., components of the tool 230. The downhole telemetry cartridge 226would in turn send the data to the TIM 222. Thus, while such aconfiguration may simplify the downhole telemetry, tool data may becommunicated to the surface unnecessarily.

Some situations may call for communicating data or a signal from onedownhole tool to another downhole tool. Such a telemetry configurationmay result in the data from the sending tool being sent to the downholetelemetry cartridge 226, from which it is communicated via an uplink tothe TIM 222 of the surface modem 220, then communicated from the TIM 222via a downlink back to a receiving tool via the downhole telemetrycartridge 226. The time required for such up-and-down communication maybe inefficient, for example in deep boreholes where the distance betweenthe downhole telemetry cartridge 226 and TIM 222 can be large.

In another configuration, inter-tool communication involvescommunication between downhole tools and is termed “inter-tool”communication herein and includes communication between downhole toolswithout traveling to and from a surface module. Examples of inter-toolcommunication techniques are provided in commonly assigned U.S. Pat. No.7,193,525, the entire contents of which are hereby incorporated byreference herein in their entirety. Inter-tool configurations may bedirected to providing a more accurate synchronization of various eventsassociated with downhole, tools, shorter time lags between commands andresponses, and/or a smaller operational overhead.

Methods and apparatus of inter-tool communication can be implemented byexamining data (including command signals) contained in an uplink datastream while the data is still local to the downhole tool. By examiningthe data before it travels to the surface, information sent by one ormore downhole tools arid intended for other downhole tools can beextracted, copied, and transmitted to intended destinations withouttravelling to the surface (i.e., the TIM 222). The shorter latencyperiod may result in better logging information and be used to providemore efficient well operation. As used herein, the term “extract” or“extracted” means to derive or obtain (information, for example) from asource.

The downhole telemetry cartridge 226 can include the downhole masternode controller 227 which may examine packets sent by each respectivetool 230, 230′, etc., and extract the uplink inter-tool communication.When there is data sent from one downhole tool (230, 230′, etc.)intended for another downhole tool (230, 230′, etc.), such data may becopied and buffered at the master node controller 227, and sent tointended downhole tools without waiting for the data to travel to thesurface and back down again. Any inter-tool communication data can besent by the downhole master node controller 227, at a subsequentdownlink period following the uplink period during which the data wasextracted.

To realize downhole inter-tool communication, which may be used toeffectively allow communication tools to send data packets in uphole anddownhole directions, an enhanced downhole toolbus protocol and downholemodule may be used. The downhole telemetry cartridge 226 may include anenhanced downhole telemetry cartridge (EDTC). Each individual tool (230,230′, etc.) may be equipped with an interface package 232, 232′, etc,,i.e., extended bus interface (XBI), a software enhanced bus interface(SERI), or a toolbus interface (BI). Further details of data extractionmethods can be found, for example, in U.S. Pat. No. 7,193,525. Eachindividual tool (230, 230′, etc.) may include a node command buffer (notshown) at the interface package 232, 232′, etc., as well as a tool nodecontroller.

Referring now to FIGS. 2 and 3, a schematic illustrating an example ofdata flow control over time illustrates a method for data flow controlof the inter-tool communication in a cable telemetry system (such as thecable telemetry system 200 of FIG. 2) to ensure message delivery bybuffering the inter-tool communication messages in another location andlater delivering when the buffer-full status of the receiver is cleared.In addition, additional inter-tool communication message requests arenot acknowledged by the system until the clear status.

In the present example, Downhole Tool Y 230′ (FIG. 3) requests to sendan inter-tool message to Downhole Tool X 230. Data is transferredbetween tools according to the data transfers as indicated by circlednumbers 1 through 9. The data transfer is performed by uplink asindicated by UL and downlink as indicated by DL.

In data transfer 1, the tool node controller 233′ for Tool Y 230′ sendsan inter-tool communication request to Tool Y's EIP 232′. In datatransfer 2, the tool node controller 233′ returns an ACK(acknowledgement) to the tool node controller 233′ of Tool Y 230′, whichallows it to write the inter-tool communication message toward Tool X230. In data transfer 3-1, the tool node controller 233′ of Tool Y 230′then writes the inter-tool communication into the interface package233′. In data transfer 3-2, the inter-tool communication message towardTool X 230 is sent to the master node controller 227.

At some point in time, Tool X 230 (the intended recipient) may send amessage (in data transfer 4) to the master node controller 227 statingthat the command buffer for Tool X 230 is full and unable to accept anynew data. In the next downlink period after receiving a command bufferfull message, the master node controller 227 sends a command bufferstatus to the interface packages 232, 232′ which are slave nodes (twoare shown in this example) stating that Tool X's command buffer is fullin data transfer 5.

The message sent by interface package 232′ of Tool Y 230′ can bebuffered in the master node controller 227 (after data transfer 3) andnot sent on to the command buffer for Tool X 230 until a later time.Tool Y's 230′ inter-tool communication message to Tool X 230 can belater sent in data transfer 9, once Tool X′s 230 command buffer iscleared from full status, and a message indicating such is transferredto the master node controller 227 in data transfer 8.

In the meantime, while the command buffer for Tool X 230 is reflecting“full” status, Tool Y's 230′ tool node controller 233′ requests in datatransfer 6 to send a second inter-tool communication message toward ToolX 230. This request is sent to Tool Y's interface package 232′. Tool Y'sinterface package 232′, since receiving a message that Tool X's receiverbuffer is full, returns a non-acknowledgement (NAK) in data transfer 7to Tool Ts tool node controller 233′. The second inter-toolcommunication message toward Tool X 230 is not sent by Tool Y's 230′tool node controller 233′ until Tool X's 230 command buffer has a clearstatus reported by the master node controller 227. In this case. ToolY's 230′ messages toward Tool X 230 are sent when Tool X 230 has thecapacity to receive commands, thereby ensuring that the messages are notlost due to full buffers.

The individual interface packages may be notified in cases where aninter-tool communication receiver node's command buffer is full or amaster node controller downlink command buffer is over threshold by a“Buffer Full Nodes” command. When the destination buffer of any giveninter-tool communication message is indicated in the “Buffer Full Nodes”command, the master node controller 227 does not send the bufferedcommand to the individual interface package 232, 232′, etc. in addition,the respective tool node controllers 233, 233′, etc., of the individualtool nodes return a non-acknowledgement (NAK) when additional inter-toolcommunication messages are requested to be sent, once the master nodecontroller 227 has distributed a buffer full status relating to aparticular tool.

Turning now FIG. 4, a flow chart is shown for a method for inter-toolcommunication data flow control in a toolbus system. The method mayinvolve the data flow control over time for a cable telemetry system asdepicted in FIGS. 2 and 3. The method begins with sending 450 an uplinkcommand message for a receiving downhole tool node (i.e., Tool X in theabove example) from a sending downhole tool node (i.e., Tool Y in theabove example) to a master downhole node.

The method continues with sending 452 a command buffer full message fromthe receiving downhole tool node to the master downhole node when areceiving node command buffer is full, The method continues with sending454 a downlink command buffer full message from the master downhole nodeto the first (or sending) downhole tool node and receiving downhole toolnode. The method continues with buffering 456 the uplink command messageby the master downhole node. The method continues with sending 458 theuplink command message to the receiving downhole tool node when thereceiving node command buffer is not full.

Referring to FIG. 5, flow control system 500 may be outlined as variousbuffers managed according to three layers 570, 572, 574, as illustratedin the block diagram schematic of FIG. 5. The flow control system 500incorporates the system of FIG. 2 and depicts operation therewith. InLayer 570, surface tool applications 238, 238′, etc.

generate commands, while individual tools 230, 230′, etc. consumecommands in downlink; and while individual tools 230, 230′, etc.generate uplink messages and surface tool applications 238, 238′, etc.consume messages in uplink.

In Layer 572, surface computer data dispatcher module 236 managescommand tool-specific buffers on the surface, and the correspondingtoolbus master node controller 227 manages toolbus-specific buffers inthe DTC 226. In Layer 574, cable telemetry manages the delivery of thecommands over the physical medium of the cable 114.

A plurality of flow control loops may be maintained across the threelayers 570, 572, 574. In Loop 590, flow control may be established forthe cable telemetry downlink layer between DTC 226 and surfaceacquisition front-end unit 119 so that the superpacket buffering space586 in DTC 226 does not overflow.

The DTM 220 may accomplish various tasks, In the presence of data, theDTM 220 maintains an average downlink data rate as needed based on thephysical layer timing. The DTM 220 may stop generating superpackets ifthere is no data to send. In case of transmission errors, the DTM 220may re-transmit downlink superpackets. In case the DTC 226 signals“Superpacket Buffer Not Available”, the DTM 220 may stop downlinksuperpacket transmission until the downhole buffer becomes available.The DTM 220 may also empty the superpacket buffer 584 if the telemetrylink fails.

As part of Loop 590, the DTC 226 may accomplish various tasks. The DTC226 may detect a superpacket error and negatively (to the DTM 220)acknowledge had packets. The DTC 226 may maintain the superpacket buffer584. In case the superpacket buffer 584 becomes full, the DTC 226 maysend a “Superpacket Buffer Not Available” status to the DTM 220, as wellas send a “Superpacket Buffer Available” to the DTM 220 when thecondition changes. The DTC 226 may empty the superpacket buffer 584 ifthe telemetry link fails, or may do so on command from the DTM 220. TheDTC 226 may periodically report the tool node buffer (588, 588′, etc.)status to the surface for record-keeping purposes.

In Loop 591, flow control is established for the cable telemetrydownlink layer between the surface acquisition front-end unit 119 andsurface computer data dispatcher module 236. The surface acquisitionfront-end unit 119 may accomplish various tasks. The surface acquisitionfront-end unit 119 may maintain a buffer 582 of downlink commands. Datafrom the buffer 582 may be used to generate downlink superpackets,thereby decoupling the sending of the data from surface computer 234from the downlink superpacket generation. The surface acquisitionfront-end unit 119 may issue “Buffer Not Available” result to surfacecomputer data dispatcher module 236 when the buffer 582 reaches athreshold value. The surface acquisition front-end unit 119 may issue a“Buffer Available” result to surface computer data dispatcher module 236when the condition changes. The surface acquisition front-end unit 119may empty the buffer 582 if the telemetry link fails.

The surface computer data dispatcher module 236 may accomplish two flowcontrol tasks in Loop 591. The surface computer data dispatcher module236 may deliver downlink data to a buffer 580 of the surface acquisitionfront-end 119 in response to a message of “Buffer Available.” Thesurface computer data dispatcher module 236 may stop delivery inresponse to a message of “Buffer Not Available.”

In Loop 592, flow control may be established for the cable telemetrydownlink layer between the buffers at the master node controller 227(i.e., a buffer specific to each tool) and the node command buffer 582,584 (also tool-node specific to each tool).

The master node controller 227 may accomplish various tasks. The masternode controller 227 may maintain a separate buffer (588, 588′, etc.) foreach tool string interface package (i.e., IP, EIP or EIP 2.0) in thetoolstring. The interface package may be, for example, part ofcontroller 232, 232′, etc. of FIG. 2. The master node controller 227 mayissue a “IP XX Buffer Not Available” to surface computer data dispatchermodule 236 when the buffer (588, 588′, etc.) for a particular IP, EIP orEIP 2.0 reaches a certain threshold percentage of its maximum value. Forexample, in an embodiment, a threshold value can be configurable fromthe surface according to the system selection based on the latency, orround trip time, differences. The master node controller 227 may issuean “IP XX Buffer Available” to surface computer data dispatcher module236 when the buffer for that IP, EIP or EIP 2.0 goes below the thresholdvalue.

The master node controller 227 may empty the buffers if the telemetrylink fails, or on command from the surface computer 234. The master nodecontroller 227 may periodically report the tool node buffer (588, 588′,etc.) status to the surface for record-keeping purposes. The surfacecomputer data dispatcher module 236 may accomplish various tasks relatedto Loop 593. The surface computer data dispatcher module 236 maymaintain a separate buffer for each IP, EIP or EIP 2.0 in thetoolstring, which may be implemented at any size or in any manner. Thesurface computer data dispatcher module 236 may allow an application fortool XX to write into the buffer (576 or 576′) if DTC 226 has sent amessage “Downlink IP XX Buffer Available,” and conversely, may not allowthe application to write if the buffer (576 or 576′) is not available,and instead at its own local buffer 580 until space permits. The surfacecomputer data dispatcher module 236 may dispatch commands from eachbuffer in such a way as to enable each tool to have the ability to sendits commands. In Loop 593, flow control is established for the cabletelemetry downlink layer between the master node controller 227 and toolnode controllers 233, 233′, etc. The master node controller 227 maymaintain a separate buffer (588, 588′, etc.) for each IP, EIP or EIP 2.0in the toolstring. The master node controller 227 may send a command toan IP, EIP or EIP 2.0 when the tool's node controller is ready to acceptthe next command. The master node controller 227 may send the toolcommands to each tool as quickly as possible, given the IP statusfeedback from the tools (e.g., acknowledgement”, “downlink bufferoverflow” and “downlink buffer full” are represented each by a singlebit within the IP status word in packet header) when dealing with IP/EIPslave nodes and similarly send tool commands to an EIP 2.0 tool as fastas possible given the EIP 2.0 status feedback. The master nodecontroller 227 may buffer a command in a tool specific buffer 586 untilthe tool is ready to accept the command. The tool node controllers 233,233′, etc. may receive and check data, as well as send statusinformation to the master node controller 227 to allow the master nodecontroller 227 to regulate the flow.

Although a few example embodiments have been described in detail above,those skilled in the art will readily appreciate that many modificationsare possible in the example embodiments without materially departingfrom this disclosure. Accordingly, such modifications are intended to beincluded within the scope of this disclosure as defined in the followingclaims. In the claims, means-plans-function clauses are intended tocover the structures described herein as performing the recited functionand not simply structural equivalents, but also equivalent structures.Thus, although a nail and a screw may not be structural equivalents inthat a nail employs a cylindrical surface to secure wooden partstogether, whereas a screw employs a helical surface, in the environmentof fastening wooden parts, a nail and a screw may be equivalentstructures. It is the express intention of the applicant not to invoke35 U.S.C. §112, paragraph 6 for any limitations of any of the claimsherein, except for those in which the claim expressly uses the words‘means for’ together with an associated function.

What is claimed is:
 1. A method for inter-tool communication in atoolbus system of a toolstring with cable telemetry, comprising:positioning downhole equipment into a wellbore via a cable, the downholeequipment comprising a toolbus master node comprising a buffer of thetoolbus master node and one or more nodes operatively coupled to thetoolbus master node via a toolbus, each of the one or more nodescomprising a buffer; sending a data message to a receiving node of theone or more nodes from a sending node of the one or more nodes via thetoolbus master node; sending a buffer full message from the receivingnode to the toolbus master node when the buffer for the receiving nodeis full; forwarding the buffer full message from the toolbus master nodeto the sending node and the receiving node; buffering the data messageat the buffer of the toolbus master node when the buffer for thereceiving node is full; and sending the data message to the receivingnode when the buffer for the receiving node is not full.
 2. The methodof claim 1, wherein sending the data message comprises sending a messagerequest from a controller of the sending node to an interface package ofthe sending node.
 3. The method of claim 2, wherein sending the datamessage further comprises returning an acknowledgement from theinterface package of the sending node to the controller of the sendingnode when the buffer for the receiving node is not full.
 4. The methodof claim 2, wherein sending the data message further comprises sending awrite command message from the controller of the sending node to theinterface package of the sending node when the buffer for the receivingnode is not full.
 5. The method of claim 2, further comprising returninga non-acknowledgement from the interface package of the sending node tothe controller of the sending node when the buffer for the receivingnode is full.
 6. The method of claim 5, further comprising inhibiting asending of a command message from the controller of the sending node tothe interface package of the sending node based on thenon-acknowledgment.
 7. A system for inter-tool communication in adownhole toolbus in cable telemetry, comprising: downhole equipmentdeployable into a wellbore via a cable, the downhole equipmentcomprising: a toolbus; a toolbus master node comprising a buffer; one ormore nodes operatively coupled to the toolbus master node via thetoolbus; each of the one or more nodes comprising a buffer; a sendingnode of the one or more nodes that sends a message; a receiving node ofthe one or more nodes that is operatively coupled to the sending nodevia the toolbus, receives the message via the toolbus master node, andsends a buffer full message to the toolbus master node when the bufferof the receiving node is full; and the toolbus master node that sendsthe buffer full message to the sending node and the receiving node whenthe buffer of the receiving node is full and buffers the message at thebuffer of the toolbus master node until the buffer of the receiving nodeis not full.
 8. The system of claim 7, wherein the toolbus master nodesends a buffered message to the receiving node when the buffer of thereceiving node is not full.
 9. The system of claim 7, wherein thereceiving node further comprises a receiving controller and a receivinginterface package; and the sending node further comprises a sendingcontroller and a sending interface package that returns anacknowledgement to the sending controller when the buffer of thereceiving node is full and returns a non-acknowledgement to the sendingcontroller when the toolbus master node receives the buffer full messagefrom the receiving node.
 10. A method for bi-directional communicationin a cable telemetry system, comprising: providing the cable telemetrysystem comprising a cable operatively coupling between a surface modemand a downhole modem, the downhole modem operatively coupled to adownhole toolstring of one or more downhole tools; configuring one of atool command and a tool measurement into a configured transmission forcommunication via the cable telemetry system; buffering the configuredtransmission at the surface modem; transmitting the configuredtransmission via the cable; buffering the configured transmission at thedownhole modem; and routing the configured transmission to one tool ofthe one or more downhole tools.
 11. The method according to claim 10,wherein configuring one of a tool command and a tool measurementcomprises: receiving the tool command from one of a plurality of surfaceapplications that analyze measurements made by the one or more downholetools; and configuring the tool command into a downlink configuredtransmission.
 12. The method according to claim 10, wherein configuringone of a tool command and a tool measurement comprises: receiving a toolmeasurement from one tool of the one or more downhole tools; andconfiguring the tool measurement into an uplink configured transmission.13. The method according to claim 10, wherein configuring one of a toolcommand and a tool measurement comprises one of partitioning, combining,modulating, demodulating, and error checking data into a format fortransmission.
 14. The method according to claim 10, further comprisingexecuting a handshake between the surface modem and the downhole modemwhereby the configured transmission is transmitted via the cable betweenthe surface modem and the downhole modem when space is available in areceiving buffer of the surface modem or the downhole modem.